IMPROVING DECELERATION OF A GAS TURBINE

A gas turbine engine 101 for an aircraft comprises a high-pressure (HP) spool comprising an HP compressor 105 and a first electric machine 117 driven by an HP turbine 107; a low-pressure (LP) spool comprising an LP compressor 104 and a second electric machine 119 driven by an LP turbine 108; a combustion system 106 comprising a fuel metering unit; and an engine controller 123 configured to, in response to a change of a power lever angle setting indicative of a deceleration event, reduce fuel flow to the combustion system 106 by the fuel metering unit, and to operate the first electric machine 117 in a generator mode to reduce the HP spool rotational speed and engine core mass flow.